Metaphyseal changes in Perthes' disease: an experimental study.

Glass microspheres were introduced into the hind-limb circulation of 6 immature Gottingen mini-pigs so as to result in ischaemia of the developing proximal femur. Radiological abnormalities similar to those seen in the metaphysis in Perthes' disease were produced in 1 animal. Histological examination shows that these resulted from arrest of a portion of necrotic growth plate within the metaphysis with a corresponding defect within the growth plate. This was associated with ischaemia of the adjacent epiphysis. These changes support the suggestion that metaphyseal change in Perthes' disease are secondary to epiphyseal ischaemia. It is possible that the growth-plate defect may be the precursor of intrinsic deformity of the femoral head.